You can put this solution on YOUR website! -10x + 2x2 – 6x3 + 5(6x + 4x2 – 3x3)= -10x + 2x^2-6x^3+30x+20x^2-15x^3 (I have opened the brackets)
now let us add the like terms
-10x+30x +2x^2 + 20 x^2-6x^3 - 15 x^3
=20x+22x^2-21x^3
This is the final answer
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